Unpacking packed data in multiple lanes

ABSTRACT

Receiving an instruction indicating first and second operands. Each of the operands having packed data elements that correspond in respective positions. A first subset of the data elements of the first operand and a first subset of the data elements of the second operand each corresponding to a first lane. A second subset of the data elements of the first operand and a second subset of the data elements of the second operand each corresponding to a second lane. Storing result, in response to instruction, including: (1) in first lane, only lowest order data elements from first subset of first operand interleaved with corresponding lowest order data elements from first subset of second operand; and (2) in second lane, only highest order data elements from second subset of first operand interleaved with corresponding highest order data elements from second subset of second operand.

BACKGROUND

1. Field

Embodiments relate to processors, methods performed by processors,systems incorporating processors, or instructions processed byprocessors. In particular, embodiments relate to processors, methods,systems, or instructions to unpack packed data in multiple lanes.

2. Background Information

Improving the performance of computers and other processing systemsgenerally tends to increase the amount of data that may be processedand/or provide a better user experience. As computer and otherprocessing systems handle increasingly larger amounts of data,techniques to expedite such processing of data tend to become moreimportant.

Single Instruction, Multiple Data (SIMD) architectures are one way toexpedite processing of data. In SIMD architectures, instead of oneinstruction operating on only one data element, the instruction mayoperate on multiple data elements simultaneously or in parallel.Representatively, in SIMD architectures multiple data elements may bepacked within one register or memory location. Parallel executionhardware responsive to the instruction may perform multiple operationssimultaneously or in parallel. Such SIMD architectures tend tosignificantly improve system performance.

One known type of SIMD instruction is an unpack instruction. Some knownprocessors include a variety of different unpack instructions. Forexample, the Intel® Core™ 2 Duo Processor, among others from IntelCorporation, includes various unpack instructions such as those detailedin the Intel Architecture Software Developer's Manual: Vol. 2:Instruction Set Reference, 1999 (Order Number 243191).

However, additional unpack instructions and operations may be usefulunder some conditions and for some applications.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Embodiments of the invention may best be understood by referring to thefollowing description and accompanying drawings that are used toillustrate embodiments of the invention. In the drawings:

FIG. 1 illustrates one example embodiment of a processor.

FIG. 2 is a block flow diagram of an embodiment of a method of receivingan instruction and storing a result specified by the instruction.

FIG. 3 shows an embodiment of YMM registers utilized by many Intel®Advanced Vector Extensions (Intel AVX) instructions.

FIG. 4 shows representative examples of packed data formats suitable forone or more embodiments of the invention.

FIG. 5 is a block flow diagram of an example embodiment of a cross-laneunpack method.

FIG. 6 illustrates unpacking 32-bit doubleword packed data elements in256-bit operands having two lanes according to a first single cross-laneunpack instruction that specifies unpack low operations for a lower laneand unpack high operations for an upper lane.

FIG. 7 illustrates unpacking 32-bit doubleword packed data elements in256-bit operands having two lanes according to a second singlecross-lane unpack instruction that specifies unpack high operations fora lower lane and unpack low operations for an upper lane.

FIG. 8 illustrates unpacking 16-bit word packed data elements in 256-bitoperands having two lanes according to a third single cross-lane unpackinstruction that specifies unpack low operations for a lower lane andunpack high operations for an upper lane.

FIG. 9 illustrates unpacking 16-bit word packed data elements in 256-bitoperands having two lanes according to a fourth single cross-lane unpackinstruction that specifies unpack high operations for a lower lane andunpack low operations for an upper lane.

FIG. 10 is a simplified block diagram of an embodiment of a cross-laneunpack instruction having a control field to specify what types ofunpack operations are to be performed for each lane.

FIG. 11 is a block diagram of an example embodiment of a computer systemthat is suitable for implementing one or more embodiments of theinvention.

DETAILED DESCRIPTION

In the following description, numerous specific details, such asprocessor types, data types, data formats, register types, registerarrangements, system configurations, and the like, are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. In other instances, well-knowncircuits, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description.

FIG. 1 illustrates one example embodiment of a processor 100. Theprocessor is capable of, or operable to, execute a cross-lane unpackinstruction 102 as discussed elsewhere herein.

The processor may be any of various different types of processors thatare capable of executing instructions. For example, the processor may bea general-purpose processor, such as a PENTIUM® 4, PENTIUM® Dual-Core,Core™ 2 Duo and Quad, Xeon™, Itanium®, XScale™ or StrongARM™microprocessor, which are available from Intel Corporation, of SantaClara, Calif. Alternatively, the processor may be from another company.The processor may be a reduced instruction set computing (RISC)processor, a complex instruction set computing (CISC) processor, a verylong instruction word (VLIW) processor, or a hybrid or alternativeprocessor type. As yet another option, the processor may be aspecial-purpose processor, such as, for example, a network orcommunication processor, co-processor, embedded processor, compressionengine, graphics processor, or the like. The processor may beimplemented on one or more chips.

During use, the processor is operable to receive the cross-lane unpackinstruction 102. The unpack instruction may represent a control signalthat is operable to cause the processor to perform unpack operations asdiscussed further below. The unpack instruction may be provided by asoftware sequence or algorithm, for example.

The illustrated embodiment of the processor includes an instructiondecoder 104. The decoder may receive the cross-lane unpack instruction.The decoder may decode the unpack instruction, and generate as an outputone or more micro-operations, micro-code entry points,microinstructions, other instructions, or other control signals, whichare decoded from, or which otherwise reflect, or are derived from, theoriginal unpack instruction. The decoder may be implemented usingvarious different mechanisms. Examples of suitable mechanisms include,but are not limited to, look-up tables, hardware implementations,programmable logic arrays (PLAs), microcode random access memories(ROMs), etc.

In some cases, the decoder may be replaced with an instructiontranslator, an instruction emulator, or other instruction converter. Theinstruction converter may convert an instruction from a sourceinstruction set to a target instruction set. For example, theinstruction converter may translate, morph, emulate, or otherwiseconvert an unpack instruction as described herein to one or more otherinstructions to be processed by an execution unit. The instructionconverter may be implemented in software, hardware, firmware, or acombination thereof. The instruction converter may be on processor, offprocessor, or part on and part off processor. Accordingly, the decoderis not a required component of the processor.

The processor includes at least one execution unit 106. The executionunit is coupled with, or otherwise in communication with, the decoder,or an instruction translator or other instruction converter as discussedabove. The execution unit may include a circuit or execution logicoperable to or capable of executing unpack instruction. For example, theexecution unit may execute one or more micro-operations,microinstructions, or other instructions or control signals, which aredecoded from, translated from, emulated from, or which otherwisereflect, or are derived from, the original unpack instruction. In one ormore embodiments, the execution unit may have specialized logic toprocess machine instructions or micro-ops or instructions derived fromthese machine instructions. That is, the execution unit may performoperations as a result of, or in response to, the cross-lane unpackinstruction. In one or more embodiments, the execution unit and/or theprocessor may perform operations as a result of, or in response to, mostor all Intel Architecture instructions, such as, for example, those usedin the PENTIUM® 4, PENTIUM® Dual-Core, Core™ 2 Duo and Quad, Xeon™,Itanium®, XScale™ or StrongARM™ microprocessors.

Some embodiments may include only a single execution unit, or a singleexecution unit that can perform certain operations. Other embodimentsmay include a number of execution units dedicated to specific functionsor sets of functions. In addition, one or more embodiments of aprocessor may have multiple cores with each core having at least oneexecution unit.

The processor also includes a register file 108 coupled with the decoderand the execution unit. The term “register” is used herein to refer to agenerally on-board processor storage location that is generally used bya macro-instruction to identify an operand. Generally, the registers arevisible from the outside of the processor or from a programmer'sperspective. The registers are not limited to any known particular typeof circuit. Various different types of registers are suitable as long asthey are capable of storing and providing data as described herein.Examples of suitable registers include, but are not limited to,dedicated physical registers, dynamically allocated physical registersusing register renaming, combinations of dedicated and dynamicallyallocated physical registers, etc.

The register file may have various different types of registers.Examples of suitable types of registers include, but are not limited to,integer registers, floating point registers, vector registers, statusregisters, instruction pointer registers, and the like.

For simplicity, a single register set 109 is shown. The register setincludes a group or number of registers. For example, the register setincludes registers R0 through RN, where N is an integer. In oneparticular embodiment, N is 15. The registers may or may not be renamed.

The register set may be adapted to store packed data. Packed datacomprises multiple data elements packed together. A data element mayrefer to an individual piece of data that is stored in a register orother storage location along with other data elements often having thesame length in bits. The register set may permit access to one orvarious ones of the packed data elements separately from others. Atdifferent times, a particular register in a register set may hold packeddata elements of different sizes, and all of the different individualsizes of packed elements may or may not all be accessible individually.

The register set has multiple lanes. In the illustrated embodiment, theregister set, including each of the registers thereof, has a first,lower lane 110 and a second, upper lane 111. The lower lane has thelower most bits, while the upper lane has the uppermost bits. Each ofthe lanes has a plurality of bits. For example, the registers may eachhave 256-bits, and each of the lanes may have 128-bits. In otherembodiments, the processor and/or the registers may have three, four, ormore lanes, and the registers and the lanes may have different sizes.

The illustrated embodiment of the processor also includes a cache 112coupled with the decoder. Depending on the architecture, the processormay have a single internal cache, such as, for example, a Level 1 (L1)internal cache, or multiple levels of internal cache. In someembodiments, the system may include a combination of an internal cacheand an external cache that is external to the processor. Alternatively,all of the cache may be external to the processor.

To avoid obscuring the description, the processor has been shown in asimplified format. It will be appreciated by those skilled in the artthat the processor may include other conventional components, circuits,or logic. For example, the processor may include front end logic,register renaming logic, scheduling logic, back end logic, retirementlogic, re-order buffers, etc. Moreover, this is just one illustrativeexample embodiment of a processor. Other general purpose processors,special purpose processors, network or communication processors,co-processors, embedded processors, compression engines, graphicsprocessors, or the like, may also benefit from the unpack instructionsand operations disclosed herein.

FIG. 2 is a block flow diagram of an embodiment of a method 214 ofreceiving an instruction and storing a result specified by theinstruction. In one or more embodiments, the method may be performed bya processor as a result of an unpack instruction as disclosed elsewhereherein.

The instruction may be received, at block 215. The instruction mayrepresent a machine instruction in an instruction set of the processor.By way of example, the instruction may be received at a processor, or ata decoder, or other portion of the processor. Representatively, theinstruction may be received from a cache, such as, for example, cache112, or a bus or other interconnect.

The instruction may be decoded, at block 216. The instruction may bedecoded into one or more micro-operations, micro-code entry points,microinstructions, other instructions, or other control signals, whichare decoded from, or which otherwise reflect, or are derived from, theoriginal unpack instruction. Alternatively, the instruction may betranslated, emulated, or otherwise converted, as previously mentioned.

The decoder or another portion of the processor may access and/orreceive one or more operands indicated by the instruction, at block 217.The operands may be accessed and/or received from registers (e.g.,register set 109), memory locations, or a combination thereof. Theinstruction may specify the addresses of the registers or memorylocations of the operands. For example, the instruction may specify anaddress of a first source operand (SRC1) and an address of a secondsource operand (SRC2).

An execution unit may be enabled with operation(s) specified by theinstruction, at block 218. The execution unit may perform the specifiedoperation(s) on the data of the operands to generate a result operand.

The result operand may be stored at a destination address of a registeror memory location specified by the instruction, at block 219. In one ormore embodiments, in addition to SRC1 and SRC2, the instruction may alsospecify an address for the result operand (DEST). Alternatively, in oneor more embodiments, either SRC1 or SRC2 may also be used as DEST. Forexample, the data at SRC1 or SRC2 may be overwritten with the resultoperand. In such a case, the instruction may not explicitly specify aseparate DEST, although the instruction is understood to specify thedestination for the result operand as one of SRC1 and SRC2.

Intel Corporation has recently introduced Intel® Advanced VectorExtensions (Intel AVX) instructions. Intel AVX provides a new 256-bitSIMD floating point vector extension to the Intel Architecture. Thiswidens or doubles the maximum SIMD vector length of the 128-bit XMMregister file in Intel® SSE4 to 256-bits. Intel AVX introduces, and manyof the Intel AVX instructions operate on, 256-bit registers referencedin assembly by the names YMM0-YMM15. Further details on Intel AVX, ifdesired, are available in the document Intel® Advanced Vector ExtensionsProgramming Reference (Ref.#319433-005), published January 2009,available from Intel Corporation, and at the time of filing available onthe web at http://software.intel.com/en-us/avx/.

FIG. 3 shows an embodiment of YMM registers 320 utilized by many IntelAVX instructions. The YMM registers include registers YMM0 throughYMM15. Each of the YMM registers has 256-bits. As shown, in one or moreembodiments, the lower 128-bits of the YMM registers are aliased to therespective 128-bit XMM registers, although this is not required. Theregisters YMM0-YMM15 are constructed from two 128-bit lanes. A lower128-bit lane 310 (bits 0 to 127) corresponds to the XMM registers. Anupper 128-bit lane 311 (bits 128 to 255) corresponds to the YMMregisters.

FIG. 4 shows representative examples of packed data formats suitable forone or more embodiments of the invention. Two example packed dataformats are illustrated, namely packed word 430, and packed doubleword432. To better illustrate certain concepts, these packed data formatsare shown for 256-bit storage locations, such as, for example, YMMregisters, although the scope of embodiments of the invention are not solimited.

Packed word format 430 is 256-bits long and includes sixteen dataelements. Each data element is 16-bits or one word long. Such 16-bitdata elements are referred to as “words”. In the illustration, the dataelements are labeled, from low order to high order, “word0” through“word15”. Word0 through word7 correspond to a lower lane (on the right;bits 0 to 127). Word8 through word15 correspond to an upper lane (on theleft; bits 128 to 255).

Packed doubleword (dword) format 432 is 256-bits long and includes 8data elements. Each data element is 32-bits or one doubleword (dword)long. Such 32-bit data elements are referred to as “dwords”. 32-bit dataelements are commonly used for single precision floating pointcalculations. In the illustration, the data elements are labeled, fromlow order to high order, “dword0” through “dword15”. Dword0 throughdword3 correspond to a lower lane. Dword4 through dword7 correspond toan upper lane.

These are just two illustrative examples. Other packed data formats arealso suitable. For example, packed byte formats, in which each dataelement has 8-bits, and packed quadword formats, in which each dataelement has 64-bits, are also suitable. 64-bit data elements arecommonly used for double precision floating point calculations. Largersizes beyond 64-bit data elements are also suitable. Moreover, registerslarger or smaller than 256-bits may be used. In general, a packed dataformat includes multiple data elements. Commonly, the data elements arethe same size. In such a case, the size of the register divided by thesize of the data elements is equal to the number of data elements.

Intel AVX utilizes registers having multiple multi-bit lanes. CertainIntel AVX instructions are known as “in-lane” instructions. Such“in-lane” instructions cause the same operation to be performed on both128-bit halves or lanes of one or more YMM registers. For example, theUNPCKLPS (VEX.256 encoded version) instruction of Intel AVX causes thesame unpack low operation to be performed on both 128-bit halves orlanes of the YMM registers. Currently, there is no known “cross-lane”unpack instruction in which different unpack operations (e.g., unpacklow versus unpack high) are performed on different lanes. Accordingly,in some applications or under some conditions, additional operations,such as extracts, casts, etc., may be needed to rearrange results ofsuch “in-lane” unpack instructions, which may require extra computationand/or complicate programming. Alternatively, use of older SSE unpackinstructions may not take full advantage of the newer 256-bit YMMregisters. Accordingly, additional unpack instructions and operationsmay be useful under some conditions or for some applications. Forexample, unpack instructions more useful for Structure of Arrays (SoA)to Array of Structures (AoS) algorithms would be beneficial

Embodiments of the invention pertain to processors, methods performed byprocessors, systems incorporating processors, or instructions executedor processed by processors to unpack packed data in multiple lanes inwhich an unpack operation performed on at least one lane is of adifferent type than an unpack operation performed on at least one otherlane. Embodiments of the invention pertain to “cross-lane” unpackinstructions that specify unpack low operations for at least one laneand unpack high operations for at least one other lane, or to processorsto process the cross-lane unpack instructions, methods performed byprocessors as a result of processing the cross-lane unpack instructions,or computer systems or other systems incorporating such processors.

FIG. 5 is a block flow diagram of an example embodiment of a cross-laneunpack method 534.

A cross-lane unpack instruction may be received, at block 535. Thecross-lane unpack instruction may specify unpack low operations for atleast one lane and unpack high operations for at least one other lane.

The cross-lane unpack instruction may be decoded, at block 536.Alternatively, the instruction may be translated, emulated, or otherwiseconverted.

First and second source operands specified or indicated by thecross-lane unpack instruction may be accessed, at block 537. Theoperands may be accessed from registers or memory locations. Thecross-lane unpack instructions may have first and second fields toindicate the operands.

An execution unit may be enabled with the unpack low operations for theat least one lane and with the unpack high operations for the at leastone other lane, at block 538.

A result specified by the cross-lane unpack instruction may be stored ina register or memory location, at block 539. The result may representthe unpack low operations performed for the at least one lane and theunpack high operations performed for the at least one other lane.

FIGS. 6-9 illustrate various example embodiments of unpacking packeddata from first and second operands having multiple lanes according to asingle cross-lane unpack instruction that specifies unpack lowoperations for at least one lane and unpack high operations for at leastone other lane.

FIG. 6 illustrates unpacking 32-bit doubleword (dword) packed dataelements in 256-bit operands having two lanes according to a firstsingle cross-lane unpack instruction that specifies unpack lowoperations for a lower lane (bits 0 to 127) and unpack high operationsfor an upper lane (bits 128 to 255).

A first source operand 650 has 256-bits and stores eight packed 32-bitor doubleword data elements. The first source operand may be stored in aregister (e.g., a YMM register), a memory, or another storage location.These data elements are labeled, from low order to high order, X0through X7. In more detail, the first source operand includes a firstdata element (X0) represented by bits 0 through 31, a second dataelement (X1) represented by bits 32 through 63, a third data element(X2) represented by bits 64 through 95, a fourth data element (X3)represented by bits 96 through 127, a fifth data element (X4)represented by bits 128 through 159, a sixth data element (X5)represented by bits 160 through 191, a seventh data element (X6)represented by bits 192 through 223, and an eighth data element (X7)represented by bits 224 through 255. Data elements X0 through X3represent a lower lane subset of data elements that correspond to thelower lane. Data elements X4 through X7 represent an upper lane subsetof data elements that correspond to the upper lane.

Similarly, a second source operand 652 has 256-bits and stores eightpacked 32-bit or dword data elements. The first source operand may bestored in a register (e.g., a YMM register), a memory, or anotherstorage location. These data elements are labeled, from low order tohigh order, Y0 through Y7. In more detail, the second source operandincludes a ninth data element (Y0) represented by bits 0 through 31, atenth data element (Y1) represented by bits 32 through 63, an eleventhdata element (Y2) represented by bits 64 through 95, a twelfth dataelement (Y3) represented by bits 96 through 127, a thirteenth dataelement (Y4) represented by bits 128 through 159, a fourteenth dataelement (Y5) represented by bits 160 through 191, a fifteenth dataelement (Y6) represented by bits 192 through 223, and a sixteenth dataelement (Y7) represented by bits 224 through 255. Data elements Y0through Y3 represent a lower lane subset of data elements thatcorrespond to a lower lane. Data elements Y4 through Y7 represent anupper lane subset of data elements that correspond to an upper lane.

A result operand 654 stores a result. The result is generated based onperforming unpack operations specified by the first cross-lane unpackinstruction. The result may be stored by an execution unit, a functionalunit, or another portion of a processor as a result of the cross-laneunpack instruction (e.g., as a result of an execution unit executing oneor more microinstructions or other instructions decoded, translated, orotherwise derived from the instruction).

The result operand has 256-bits and stores eight packed 32-bit ordoubleword data elements. The eight data elements in the result operandrepresent a subset, less than all, or half of the unpacked andinterleaved data elements selected from the first and second sourceoperands according to unpack operations specified by the firstcross-lane unpack instruction.

This particular first cross-lane unpack instruction specifies unpack lowoperations for the lower lane (bits 0 to 127) and unpack high operationsfor the upper lane (bits 128 to 255). The unpack low operations for thelower lane may include an interleaved unpack of only the low order32-bit or doubleword data elements from the low order quadwords(64-bits) in the lower lane of the first and second source operands. Theunpack high operations for the upper lane may include an interleavedunpack of only the high order 32-bit or doubleword data elements fromthe high order quadwords (64-bits) in the upper lane of the first andsecond source operands.

As shown, the result stored may include: (1) in the lower lane, onlylowest order data elements from the lower lane subset of the firstoperand interleaved with corresponding lowest order data elements fromthe lower lane subset of the second operand; and (2) in the upper lane,only highest order data elements from the upper lane subset of the firstoperand interleaved with corresponding highest order data elements fromthe upper lane subset of the second operand.

In more detail, the result operand may include the first data element(X0) stored to bits 0 through 31 of a destination register, the ninthdata element (Y0) stored to bits 32 through 63 of the destinationregister, the second data element (X1) stored to bits 64 through 95 ofthe destination register, the tenth data element (Y1) stored to bits 96through 127 of the destination register, the seventh data element (X6)stored to bits 128 through 159 of the destination register, thefifteenth data element (Y6) stored to bits 160 through 191 of thedestination register, the eighth data element (X7) stored to bits 192through 223 of the destination register, and the sixteenth data element(Y7) stored to bits 224 through 255 of the destination register.

The result operand has only a subset (in particular half) of the dataelements from the first and second operands. The lower lane of theresult operand has only a subset (in particular half) of the dataelements from the lower lane of the first and second operands. Likewise,the upper lane of the result operand has only a subset (in particularhalf) of the data elements from the upper lane of the first and secondoperands.

Also, the lower order data elements X0 and X1, and also the lower orderdata elements Y0 and Y1, are stored in the same relative order (i.e., X0at a lower bit order than X1; and Y0 at a lower bit order than Y1) inthe lower lane of the result operand as these data elements appear inthe lower lane of the first and second operands, respectively. Likewise,the higher order data elements X6 and X7, and also the higher order dataelements Y6 and Y7, are stored in the same relative order in the upperlane of the result operand as these data elements appear in the upperlane of the first and second operands, respectively.

FIG. 7 illustrates unpacking 32-bit doubleword (dword) packed dataelements in 256-bit operands having two lanes according to a secondsingle cross-lane unpack instruction that specifies unpack highoperations for a lower lane (bits 0 to 127) and unpack low operationsfor an upper lane (bits 128 to 255).

A first source operand 750 has 256-bits and stores eight packed 32-bitor doubleword data elements. The first source operand may be stored in aregister (e.g., a YMM register), a memory, or another storage location.These data elements are labeled, from low order to high order, X0through X7. In more detail, the first source operand includes a firstdata element (X0) represented by bits 0 through 31, a second dataelement (X1) represented by bits 32 through 63, a third data element(X2) represented by bits 64 through 95, a fourth data element (X3)represented by bits 96 through 127, a fifth data element (X4)represented by bits 128 through 159, a sixth data element (X5)represented by bits 160 through 191, a seventh data element (X6)represented by bits 192 through 223, and an eighth data element (X7)represented by bits 224 through 255. Data elements X0 through X3correspond to the lower lane. Data elements X4 through X7 correspond tothe upper lane.

Similarly, a second source operand 752 has 256-bits and stores eightpacked 32-bit or dword data elements. The first source operand may bestored in a register (e.g., a YMM register), a memory, or anotherstorage location. These data elements are labeled, from low order tohigh order, Y0 through Y7. In more detail, the second source operandincludes a ninth data element (Y0) represented by bits 0 through 31, atenth data element (Y1) represented by bits 32 through 63, an eleventhdata element (Y2) represented by bits 64 through 95, a twelfth dataelement (Y3) represented by bits 96 through 127, a thirteenth dataelement (Y4) represented by bits 128 through 159, a fourteenth dataelement (Y5) represented by bits 160 through 191, a fifteenth dataelement (Y6) represented by bits 192 through 223, and a sixteenth dataelement (Y7) represented by bits 224 through 255. Data elements Y0through Y3 correspond to a lower lane. Data elements Y4 through Y7correspond to an upper lane.

A result operand 754 stores a result. The result is generated based onperforming unpack operations specified by the second cross-lane unpackinstruction. The result may be stored by an execution unit, a functionalunit, or another portion of a processor as a result of the cross-laneunpack instruction (e.g., as a result of an execution unit executing oneor more microinstructions or other instructions decoded, translated, orotherwise derived from the instruction).

The result operand has 256-bits and stores eight packed 32-bit ordoubleword data elements. The eight data elements in the result operandrepresent a subset, less than all, or in this case half of the unpackedand interleaved data elements selected from the first and second sourceoperands according to unpack operations specified by the secondcross-lane unpack instruction.

This particular second cross-lane unpack instruction specifies unpackhigh operations for the lower lane (bits 0 to 127) and unpack lowoperations for the upper lane (bits 128 to 255). The unpack highoperations for the lower lane may include an interleaved unpack of thehigh order 32-bit or doubleword data elements from the high orderquadwords (64-bits) in the lower lane of the first and second sourceoperands. The unpack low operations for the upper lane may include aninterleaved unpack of the low order 32-bit or doubleword data elementsfrom the low order quadwords (64-bits) in the upper lane of the firstand second source operands.

As shown, the result operand may include the third data element (X2)stored to bits 0 through 31 of a destination register, the eleventh dataelement (Y2) stored to bits 32 through 63 of the destination register,the fourth data element (X3) stored to bits 64 through 95 of thedestination register, the twelvth data element (Y3) stored to bits 96through 127 of the destination register, the fifth data element (X4)stored to bits 128 through 159 of the destination register, thethirteenth data element (Y4) stored to bits 160 through 191 of thedestination register, the sixth data element (X5) stored to bits 192through 223 of the destination register, and the fourteenth data element(Y5) stored to bits 224 through 255 of the destination register.

FIG. 8 illustrates unpacking 16-bit word packed data elements in 256-bitoperands having two lanes according to a third single cross-lane unpackinstruction that specifies unpack low operations for a lower lane (bits0 to 127) and unpack high operations for an upper lane (bits 128 to255).

A first source operand 850 has 256-bits and stores sixteen packed 16-bitor word data elements. The first source operand may be stored in aregister (e.g., a YMM register), a memory, or another storage location.These data elements are labeled, from low order to high order, X0through X15. Data elements X0 through X7 correspond to the lower lane.Data elements X8 through X15 correspond to the upper lane.

Similarly, a second source operand 852 has 256-bits and stores sixteenpacked 16-bit or word data elements. The first source operand may bestored in a register (e.g., a YMM register), a memory, or anotherstorage location. These data elements are labeled, from low order tohigh order, Y0 through Y15. Data elements Y0 through Y7 correspond to alower lane. Data elements Y8 through Y15 correspond to an upper lane.

A result operand 854 stores a result. The result is generated based onperforming unpack operations specified by the third cross-lane unpackinstruction. The result may be stored by an execution unit, a functionalunit, or another portion of a processor as a result of the cross-laneunpack instruction (e.g., as a result of an execution unit executing oneor more microinstructions or other instructions decoded, translated, orotherwise derived from the instruction).

The result operand has 256-bits and stores sixteen packed 16-bit or worddata elements. The sixteen data elements in the result operand representa subset, less than all, or half of the unpacked and interleaved dataelements selected from the first and second source operands according tounpack operations specified by the third cross-lane unpack instruction.

This particular third cross-lane unpack instruction specifies unpack lowoperations for the lower lane (bits 0 to 127) and unpack high operationsfor the upper lane (bits 128 to 255). The unpack low operations for thelower lane may include an interleaved unpack of the low order 16-bit orword data elements from the low order quadwords (64-bits) in the lowerlane of the first and second source operands. The unpack high operationsfor the upper lane may include an interleaved unpack of the high order16-bit or word data elements from the high order quadwords (64-bits) inthe upper lane of the first and second source operands.

As shown, the result operand includes, from low order to high order, theordered data elements X0, Y0, X1, Y1, X2, Y2, X3, Y3 in the lower lane.The result operand includes, from low order to high order, the ordereddata elements X12, Y12, X13, Y13, X14, Y14, X15, Y15 in the upper lane.

FIG. 9 illustrates unpacking 16-bit word packed data elements in 256-bitoperands having two lanes according to a fourth single cross-lane unpackinstruction that specifies unpack high operations for a lower lane (bits0 to 127) and unpack low operations for an upper lane (bits 128 to 255).

A first source operand 950 has 256-bits and stores sixteen packed 16-bitor word data elements. The first source operand may be stored in aregister (e.g., a YMM register), a memory, or another storage location.These data elements are labeled, from low order to high order, X0through X15. Data elements X0 through X7 correspond to the lower lane.Data elements X8 through X15 correspond to the upper lane.

Similarly, a second source operand 952 has 256-bits and stores sixteenpacked 16-bit or word data elements. The first source operand may bestored in a register (e.g., a YMM register), a memory, or anotherstorage location. These data elements are labeled, from low order tohigh order, Y0 through Y15. Data elements Y0 through Y7 correspond to alower lane. Data elements Y8 through Y15 correspond to an upper lane.

A result operand 954 stores a result. The result is generated based onperforming unpack operations specified by the fourth cross-lane unpackinstruction. The result may be stored by an execution unit, a functionalunit, or another portion of a processor as a result of the cross-laneunpack instruction (e.g., as a result of an execution unit executing oneor more microinstructions or other instructions decoded, translated, orotherwise derived from the instruction).

The result operand has 256-bits and stores sixteen packed 16-bit or worddata elements. The sixteen data elements in the result operand representa subset, less than all, or half of the unpacked and interleaved dataelements selected from the first and second source operands according tounpack operations specified by the fourth cross-lane unpack instruction.

This particular fourth cross-lane unpack instruction specifies unpackhigh operations for the lower lane (bits 0 to 127) and unpack lowoperations for the upper lane (bits 128 to 255). The unpack highoperations for the lower lane may include an interleaved unpack of thehigh order 16-bit or word data elements from the high order quadwords(64-bits) in the lower lane of the first and second source operands. Theunpack low operations for the upper lane may include an interleavedunpack of the low order 16-bit or word data elements from the low orderquadwords (64-bits) in the upper lane of the first and second sourceoperands.

As shown, the result operand includes, from low order to high order, theordered data elements X4, Y4, X5, Y5, X6, Y6, X7, Y7 in the lower lane.The result operand includes, from low order to high order, the ordereddata elements X8, Y8, X9, Y9, X10, Y10, X11, Y11 in the upper lane.

As shown in each of FIGS. 6-9, the result operands have only a subset(in particular half) of the data elements from the first and secondoperands. The lower lanes of the result operands have only a subset (inparticular half) of the data elements from the lower lane of the firstand second operands. Likewise, the upper lanes of the result operandshave only a subset (in particular half) of the data elements from theupper lane of the first and second operands.

Also, data elements from the first and second operands are stored in theresult operand in the same order as these data elements appear in thefirst and second operands, respectively. This is true for the resultoperand overall, as well as within each lane.

In FIGS. 6-9, 256-bit operands having two 128-bit lanes have beendiscussed, although the scope of embodiments of the invention are not solimited. The operands may have either fewer or more bits. Likewise, thelanes may have either fewer or more bits. As one illustrative example,the operands may be 128-bits and the lanes may be 64-bits. As anotherillustrative example, the operands may have 512-bits and the lanes mayhave 64-bits or 128-bits.

To further illustrate certain concepts, consider one example use of anexample cross-lane unpack instruction. In certain algorithms, such as,for example, a Structure of Arrays (SoA) to Array of Structures (AoS)algorithm, it is desirable to interleave data elements from two operandswhile maintaining the same order that the data elements appear in theoperands. Listed below is a first source operand having four dataelements (0, 2, 4, 6) duplicated in lower lane and an upper lane.Likewise, a second source operand has another four data elements (1, 3,5, 7) duplicated in the lower lane and the upper lane. By way ofexample, these data elements may be replicated by the Intel AVXbroadcast instruction. As shown below, a cross-lane unpack instructionspecifying unpack low operations for the low lane and unpack highoperations for the high lane may achieve a result operand in which allof the data elements from the first and second operands are interleavedand ordered in the same order as these data elements appear in thesource operands and the results are continuous.

a. First Source Operand: 6 4 2 0 6 4 2 0 b. Second Source Operand: 7 5 31 7 5 3 1 c. Result Operand: 7 6 5 4 3 2 1 0

This is just one illustrative example that illustrates one specific useof a particular cross-lane unpack instruction. Other uses and advantagesof the cross-lane unpack instructions will be apparent to those skilledin the art and having the benefit of the present disclosure.

FIG. 10 is a simplified block diagram of an embodiment of a cross-laneunpack instruction 1002 having a control field 1060 to specify whattypes of unpack operations are to be performed. The control field has aplurality of bits. In the illustration, a first bit (bit₀) correspondsto a first lane, a second bit (bit₁) corresponds to a second lane, andan Nth bit (bit_(N)) corresponds to an Nth lane, where N is an integeroften ranging from 2-5. In one or more embodiments, each bit may have afirst predetermined value (e.g., 0) to indicate a first type of unpackoperation (e.g., unpack low operations) for the corresponding lane and asecond predetermined value (e.g., 1) to indicate a second type of unpackoperation (e.g., unpack high operations) for the corresponding lane.Alternatively, two, three, or more bits may optionally be used tospecify the unpack operations for each lane. Alternatively, rather thanan instruction having a control field to specify what operations areperformed, an instruction may perform a single predetermined combinationof unpack operations, and if desired multiple instructions may beincluded to provide multiple different combinations of unpackoperations.

FIG. 11 is a block diagram of an example embodiment of a computer system1170 that is suitable for implementing one or more embodiments of theinvention. The computer system is representative of processing systemssuch as those based on the PENTIUM® 4, PENTIUM® Dual-Core, Core™ 2 Duoand Quad, Xeon™, Itanium®, XScale™ and/or StrongARM™ microprocessors.However, this is just one particular example of a suitable computersystem. Multi-processor systems, servers, and other computer systemshaving other designs or components are also suitable.

In one embodiment, the computer system may execute a version of theWINDOWS™ operating system, available from Microsoft Corporation ofRedmond, Wash. Alternatively, other operating systems, such as, forexample, UNIX, Linux, or embedded systems, may be used. Embodiments ofthe invention are not limited to any known specific combination ofhardware circuitry and software.

The computer system includes a processor 1100. The processor includes atleast one execution unit 1106. The execution unit and/or the processormay be capable of executing or otherwise processing at least onecross-lane unpack instruction 1102, as previously described. Theprocessor also includes a register file 1108. In one or moreembodiments, the register file includes registers having multiple lanes.That is, the processor may provide a SIMD architecture with multiplelanes. The illustrated processor is shown in a simplified format toavoid obscuring the description. It is to be appreciated that theprocessor may include other components, such as, for example, a cache,an instruction prefetcher, an instruction decoder or translator, a tracecache, a microcode (ucode) read only memory (ROM), an out of orderengine, etc.

The processor is coupled to a processor bus or other interconnect 1172.The processor bus may be used to transmit data signals between theprocessor and other components in the system.

The computer system also includes a memory 1174. The memory may includea dynamic random access memory (DRAM), a static random access memory(SRAM), flash memory, other known types of memory, or a combinationthereof. DRAM is an example of a type of memory used in some but not allcomputer systems. The memory may be used to store instructions 1173,such as software including one or more cross-lane unpack instructions,and data 1174.

The computer system is an example of a hub type architecture. The hubtype architecture includes a memory controller hub (MCH) 1176. The MCHis a system logic chip. The MCH is coupled to the processor bus 1172 andthe memory 1174. The processor may communicate with the MCH through theprocessor bus. The MCH may direct signals between the processor, thememory, and other components in the computer system. The MCH may alsobridge signals between the processor bus, the memory, and a hubinterface bus or other interconnect. The MCH provides a high bandwidthmemory path to the memory that may be used to store and retrieveinstructions and data.

In some embodiments, the system may optionally include a graphics device(e.g., a graphics/video card) 1186. The MCH may provide a graphics portand interconnect (e.g., an Accelerated Graphics Port (AGP) interconnect)to couple the graphics device.

The system also includes an I/O controller hub (ICH) 1178. The ICH iscoupled to the MCH through hub interface bus or other interconnect 1177that may include one or more buses. The ICH may provide directconnections to some I/O devices through a local I/O bus or otherinterconnect. The local I/O bus or other interconnect may represent ahigh-speed I/O bus or other interconnect to connect peripherals to thememory, the chipset, and the processor.

Several representative examples of peripherals are shown including anaudio controller 1179, flash BIOS 1180, a wireless transceiver 1181, adata storage 1182 (e.g., a hard disk drive, a floppy disk drive, aCD-ROM device, a flash memory device, or the like), a legacy I/Ocontroller 1183 to provide a user input interface (e.g., a keyboard), aserial expansion port 1184, such as a Universal Serial Bus (USB), and anetwork controller 1185. These particular peripherals are optional andnot required.

It is to be appreciated that this is just one illustrative example of asuitable computer system. The scope of embodiments of the invention arenot limited to any particular computer system design. Rather, a widevariety of other computer system designs are suitable. Such designsinclude, among others, those of laptops, desktops, engineeringworkstations, and servers, handheld PCs, personal digital assistants,and the like.

Moreover, embodiments may be applied in other devices having one or moreprocessors or execution units. For example, other devices that mayinclude a processor and/or execution unit operable to process one of thecross-lane unpack instructions disclosed herein include, but are notlimited to, portable media players, cell phones, hand held devices,Internet Protocol devices, set-top boxes, network devices, network hubs,wide area network (WAN) switches, video game devices, graphics devices,digital signal processors (DSPs), micro controllers, embeddedprocessors, and other logic circuits. Any electronic device or systemthat utilizes or may benefit from SIMD or packed data may potentiallyinclude logic to process a cross-lane unpack instruction as disclosedherein.

In the description and claims, the terms “coupled” and “connected,”along with their derivatives, may be used. It should be understood thatthese terms are not intended as synonyms for each other. Rather, inparticular embodiments, “connected” may be used to indicate that two ormore elements are in direct physical or electrical contact with eachother. “Coupled” may mean that two or more elements are in directphysical or electrical contact. However, “coupled” may also mean thattwo or more elements are not in direct contact with each other, but yetstill co-operate or interact with each other.

In the description above, for the purposes of explanation, numerousspecific details have been set forth in order to provide a thoroughunderstanding of the embodiments of the invention. It will be apparenthowever, to one skilled in the art, that one or more other embodimentsmay be practiced without some of these specific details. The particularembodiments described are not provided to limit the invention but toillustrate embodiments of the invention. The scope of the invention isnot to be determined by the specific examples provided above but only bythe claims below. In other instances, well-known circuits, structures,devices, and operations have been shown in block diagram form or withoutdetail in order to avoid obscuring the understanding of the description.Where considered appropriate, reference numerals or terminal portions ofreference numerals have been repeated among the figures to indicatecorresponding or analogous elements, which may optionally have similarcharacteristics.

Various operations and methods have been described. Some of the methodshave been described in a basic form, but operations may optionally beadded to and/or removed from the methods. The operations of the methodsmay also often optionally be performed in different order. Manymodifications and adaptations may be made to the methods and arecontemplated.

Certain operations may be performed by hardware components, or may beembodied in machine-executable instructions, that may be used to cause,or at least result in, a circuit or hardware programmed with theinstructions performing the operations. The circuit may include ageneral-purpose or special-purpose processor, or logic circuit, to namejust a few examples. The operations may also optionally be performed bya combination of hardware and software. A processor may include specificlogic responsive to a machine instruction or one or more control signalsderived from the machine instruction.

One or more embodiments of the invention may be provided as a programproduct or other article of manufacture that may include a tangiblemachine-accessible and/or readable medium having stored thereon one ormore instructions (e.g., an unpack instruction) and/or data structures.The tangible medium may include one or more materials. The medium mayprovide instructions, which, if and when executed by a machine, mayresult in and/or cause the machine to perform one or more of theoperations or methods disclosed herein. Suitable machines include, butare not limited to, computer systems, network devices, personal digitalassistants (PDAs), modems, cellular phones, other wireless devices, anda wide variety of other electronic devices with one or more processors,to name just a few examples.

The medium may include, a mechanism that provides, for example stores,information in a form that is accessible by the machine. For example,the medium may optionally include recordable mediums, such as, forexample, floppy diskette, optical storage medium, optical disk, CD-ROM,magnetic disk, magneto-optical disk, read only memory (ROM),programmable ROM (PROM), erasable-and-programmable ROM (EPROM),electrically-erasable-and-programmable ROM (EEPROM), random accessmemory (RAM), static-RAM (SRAM), dynamic-RAM (DRAM), Flash memory, andcombinations thereof.

It should also be appreciated that reference throughout thisspecification to “one embodiment”, “an embodiment”, or “one or moreembodiments”, for example, means that a particular feature may beincluded in the practice of embodiments of the invention. Similarly, itshould be appreciated that in the description various features aresometimes grouped together in a single embodiment, Figure, ordescription thereof for the purpose of streamlining the disclosure andaiding in the understanding of various inventive aspects. This method ofdisclosure, however, is not to be interpreted as reflecting an intentionthat the invention requires more features than are expressly recited ineach claim. Rather, as the following claims reflect, inventive aspectsmay lie in less than all features of a single disclosed embodiment.Thus, the claims following the Detailed Description are hereby expresslyincorporated into this Detailed Description, with each claim standing onits own as a separate embodiment of the invention.

1. A method comprising: receiving an instruction, the instructionindicating a first operand and a second operand, each of the first andsecond operands having a plurality of packed data elements thatcorrespond in respective positions, a first subset of the packed dataelements of the first operand and a first subset of the packed dataelements of the second operand each corresponding to a first lane, and asecond subset of the packed data elements of the first operand and asecond subset of the packed data elements of the second operand eachcorresponding to a second lane; and storing a result in response to theinstruction, the result including: (1) in the first lane, only lowestorder data elements from the first subset of the first operandinterleaved with corresponding lowest order data elements from the firstsubset of the second operand; and (2) in the second lane, only highestorder data elements from the second subset of the first operandinterleaved with corresponding highest order data elements from thesecond subset of the second operand.
 2. The method of claim 1, whereinthe first lane comprises a lower lane and the second lane comprises anupper lane.
 3. The method of claim 1, wherein the first lane comprisesan upper lane and the second lane comprises a lower lane.
 4. The methodof claim 1, wherein the instruction includes a control field, whereinone or more bits of the control field correspond to the first lane andindicate that an unpack low operation is to be performed for the firstlane, and wherein one or more bits of the control field correspond tothe second lane and indicate that an unpack high operation is to beperformed for the second lane.
 5. The method of claim 1, wherein each ofthe first and second lanes has 128-bits.
 6. The method of claim 1,wherein storing the result comprises: in the first lane, storing onlyhalf of the data elements from the first subsets including storing thelowest order data elements from the first subset of the first operand ina same order as the lowest order data elements appear in the firstsubset of the first operand; and in the second lane, storing only halfof the data elements from the second subsets.
 7. The method of claim 1,further comprising at least one of decoding the instruction into one ormore instructions and translating the instruction into one or moreinstructions.
 8. An apparatus comprising: an execution unit that isoperable as a result of an instruction to store a result, in which theinstruction has a first field to indicate a first operand and a secondfield to indicate a second operand, each of the first and secondoperands to have a plurality of packed data elements that are tocorrespond in respective positions, in which a first subset of thepacked data elements of the first operand and a first subset of thepacked data elements of the second operand are each to correspond to afirst lane, and in which a second subset of the packed data elements ofthe first operand and a second subset of the packed data elements of thesecond operand are each to correspond to a second lane, in which theresult that is to be stored is to include: (1) in the first lane, onlylowest order data elements from the first subset of the first operandinterleaved with corresponding lowest order data elements from the firstsubset of the second operand; and (2) in the second lane, only highestorder data elements from the second subset of the first operandinterleaved with corresponding highest order data elements from thesecond subset of the second operand.
 9. The apparatus of claim 8,wherein the first lane comprises a lower lane and the second lanecomprises an upper lane.
 10. The apparatus of claim 8, wherein the firstlane comprises an upper lane and the second lane comprises a lower lane.11. The apparatus of claim 8, wherein the instruction includes a controlfield, wherein one or more bits of the control field correspond to thefirst lane and indicate that the lowest order data elements of the firstand second operands are to be unpacked, and wherein one or more bits ofthe control field correspond to the second lane and indicate that thehighest order data elements of the first and second operands are to beunpacked.
 12. The apparatus of claim 8, wherein the instruction has athird field, which is different than the first and second fields, toindicate a destination where the result is to be stored, and whereinstoring the result comprises storing the result at the destination. 13.The apparatus of claim 8, wherein the instruction comprises a cross-laneunpack instruction.
 14. The apparatus of claim 8, wherein each of thefirst and second lanes has 128-bits.
 15. The apparatus of claim 8,wherein the execution unit is to store a result that comprises: (1) inthe first lane, only half of the data elements from the first subsets;and (2) in the second lane, only half of the data elements from thesecond subsets.
 16. The apparatus of claim 8, wherein the execution unitis to store a result that comprises, in the first lane, the lowest orderdata elements from the first subset of the first operand in a same orderas the lowest order data elements appear in the first subset of thefirst operand.
 17. The apparatus of claim 8, wherein the execution unitis to store a result that comprises at least four data elements eachfrom one of the first and second operands.
 18. The apparatus of claim 8,further comprising at least one of a decoder to decode the instructioninto one or more instructions that are to be executed by the executionunit to cause the execution unit to store the result and an instructiontranslator to translate the instruction into one or more instructionsthat are to be executed by the execution unit to cause the executionunit to store the result.
 19. The apparatus of claim 8, wherein theexecution unit comprises a circuit, and wherein the instructioncomprises a machine instruction, and wherein the execution unitcomprises particular logic operable to store the result due to themachine instruction.
 20. An apparatus comprising: a first 256-bitregister to store a first source operand including a first data elementrepresented by bits 0 through 31, a second data element represented bybits 32 through 63, a third data element represented by bits 64 through95, a fourth data element represented by bits 96 through 127, a fifthdata element represented by bits 128 through 159, a sixth data elementrepresented by bits 160 through 191, a seventh data element representedby bits 192 through 223, and an eighth data element represented by bits224 through 255; a second 256-bit register to store a second sourceoperand including a ninth data element represented by bits 0 through 31,a tenth data element represented by bits 32 through 63, an eleventh dataelement represented by bits 64 through 95, a twelfth data elementrepresented by bits 96 through 127, a thirteenth data elementrepresented by bits 128 through 159, a fourteenth data elementrepresented by bits 160 through 191, a fifteenth data elementrepresented by bits 192 through 223, and a sixteenth data elementrepresented by bits 224 through 255; an execution unit as a result of aninstruction to store a result, the result that is to be stored toinclude the first data element to be stored to bits 0 through 31 of adestination register, the ninth data element to be stored to bits 32through 63 of the destination register, the second data element to bestored to bits 64 through 95 of the destination register, the tenth dataelement to be stored to bits 96 through 127 of the destination register,the seventh data element to be stored to bits 128 through 159 of thedestination register, the fifteenth data element to be stored to bits160 through 191 of the destination register, the eighth data element tobe stored to bits 192 through 223 of the destination register, and thesixteenth data element to be stored to bits 224 through 255 of thedestination register.
 21. The apparatus of claim 20, further comprisingat least one of a decoder to decode the instruction into one or moreinstructions that are to be executed by the execution unit to cause theexecution unit to store the result and an instruction translator totranslate the instruction into one or more instructions that are to beexecuted by the execution unit to cause the execution unit to store theresult.
 22. An apparatus comprising: a first 256-bit register to store afirst source operand including a first data element represented by bits0 through 31, a second data element represented by bits 32 through 63, athird data element represented by bits 64 through 95, a fourth dataelement represented by bits 96 through 127, a fifth data elementrepresented by bits 128 through 159, a sixth data element represented bybits 160 through 191, a seventh data element represented by bits 192through 223, and an eighth data element represented by bits 224 through255; a second 256-bit register to store a second source operandincluding a ninth data element represented by bits 0 through 31, a tenthdata element represented by bits 32 through 63, an eleventh data elementrepresented by bits 64 through 95, a twelfth data element represented bybits 96 through 127, a thirteenth data element represented by bits 128through 159, a fourteenth data element represented by bits 160 through191, a fifteenth data element represented by bits 192 through 223, and asixteenth data element represented by bits 224 through 255; an executionunit as a result of an instruction to store a result, the result that isto be stored to include the third data element to be stored to bits 0through 31 of a destination register, the eleventh data element to bestored to bits 32 through 63 of the destination register, the fourthdata element to be stored to bits 64 through 95 of the destinationregister, the twelfth data element to be stored to bits 96 through 127of the destination register, the fifth data element to be stored to bits128 through 159 of the destination register, the thirteenth data elementto be stored to bits 160 through 191 of the destination register, thesixth data element to be stored to bits 192 through 223 of thedestination register, and the fourteenth data element to be stored tobits 224 through 255 of the destination register.
 23. The apparatus ofclaim 22, further comprising at least one of a decoder to decode theinstruction into one or more instructions that are to be executed by theexecution unit to cause the execution unit to store the result and aninstruction translator to translate the instruction into one or moreinstructions that are to be executed by the execution unit to cause theexecution unit to store the result.
 24. A system comprising: aninterconnect; a processor coupled with the interconnect, the processorincluding: at least one of an instruction decoder, an instructiontranslator, and an instruction emulator, the at least one implemented inhardware, software, firmware, or a combination thereof, to receive aninstruction, the instruction having a first field to indicate a firstoperand and a second field to indicate a second operand, each of thefirst and second operands to have a plurality of packed data elementsthat are to correspond in respective positions, in which a first subsetof the packed data elements of the first operand and a first subset ofthe packed data elements of the second operand are each to correspond toa first lane, and in which a second subset of the packed data elementsof the first operand and a second subset of the packed data elements ofthe second operand are each to correspond to a second lane; and acircuit responsive to said at least one receiving the instruction tostore a result, the result to include: (1) in the first lane, onlylowest order data elements from the first subset of the first operandinterleaved with corresponding lowest order data elements from the firstsubset of the second operand; and (2) in the second lane, only highestorder data elements from the second subset of the first operandinterleaved with corresponding highest order data elements from thesecond subset of the second operand; and a dynamic random access memory(DRAM) coupled with the interconnect.
 25. The system of claim 24,wherein the circuit is to store a result that comprises: (1) in thefirst lane, only half of the data elements from the first subsets; and(2) in the second lane, only half of the data elements from the secondsubsets.
 26. An article of manufacture comprising: a machine-readablemedium to provide an instruction, the instruction including a firstfield to indicate a first operand and a second field to indicate asecond operand, each of the first and second operands to have aplurality of packed data elements that are to correspond in respectivepositions, a first subset of the packed data elements of the firstoperand and a first subset of the packed data elements of the secondoperand to each correspond to a first lane, and a second subset of thepacked data elements of the first operand and a second subset of thepacked data elements of the second operand to each correspond to asecond lane, and the instruction if processed by a machine to cause themachine to perform operations comprising storing a result, the resultincluding: (1) in the first lane, only lowest order data elements fromthe first subset of the first operand interleaved with correspondinglowest order data elements from the first subset of the second operand;and (2) in the second lane, only highest order data elements from thesecond subset of the first operand interleaved with correspondinghighest order data elements from the second subset of the secondoperand.
 27. The method of claim 26, wherein the instruction comprises amachine instruction and the machine comprises particular logic operableto store the result due to the machine instruction.